1. Field of the Invention
The invention relates to a method for the operation of a wind energy plant, wherein the wind energy plant has a rotor with a rotor axis and at least one rotor blade arranged on the rotor, wherein the rotor blade is adjustable or adjusted around a rotor blade axis with a predetermined rotor blade pitch angle. Moreover, the invention relates to a wind energy plant with a rotor and at least one angle-adjustable rotor blade arranged on the rotor.
2. Description of Related Art
Wind energy plants of the patent applicant are known under the designation 5M, MM92, MM82, MM70 and MD77.
These known wind energy plants have a rotor with three rotor blades, wherein the rotor is coupled with a generator for the creation of an electrical power output. The generator is also coupled with an electrical network of a network operator, in order to supply created electrical energy to the network.
In many wind energy plants, the rotor blades are designed in an angle-adjustable manner around their rotor blade axes. In this manner, e.g., the alignment of the rotor blade can be adjusted depending on the amount of wind such that the energy received from the wind can be controlled or adjusted. In order to adjust the rotor blades, the wind energy plants are designed such that at least one blade adjustment system is provided for all three rotor blades.
The wind energy plants preferably have at least one rotor blade pitch device for each rotor blade, wherein the rotor blade pitch device has among other things a blade pitch drive with a drive motor. As a general rule, the relatively high speed of the rotor blade drive motor is transmitted to a slowly rotating drive wheel, which meshes with a sprocket directly connected with the rotor blade, via a gear box with a high transmission ratio. Furthermore, the rotor blade pitch device has a control device, via which the blade pitch drive is controlled.
For reasons of operating safety, these wind energy plants with so-called pitch-adjustable rotor blades generally have an emergency drive device with autarkic energy storage, for example an accumulator. This emergency drive device with its own energy storage is considered a reserve for failures, in particular when the main system for the pitch adjustment drive or rotor blade pitch drive no longer works due to a defect or due to the failure of the energy supply. The emergency drive device is provided in order to also be able to safely shut down the wind energy plant under these circumstances.
As a general rule, the wind energy plants are shut down by rotating the rotor blades into the so-called feathering position. The feathering position characterizes the rotating of the rotor blades out of the wind so that only a minimal contact surface is made available to the wind, as in the case of a flag, and the system is thus stopped or at least only driven into a very slow rotational movement. The wind energy plant will thus actuate the rotor blades by means of a pitch circuit in a normal operating mode and by means of an emergency circuit in an emergency mode.
Starting from this state of the art, the object of the invention is to improve the operation of a wind energy plant and to simplify in particular the maintenance of a wind energy plant.